In the art of fuel cells, there is that special class of fuel cells called "metal/air fuel cells" which include anode sections characterized by anode electrode plates of suitable metal fuel immersed in anodic electrolytes or anolytes; and cathode sections which include cathode electrode plates of current conducting catalytic material having one surface contacting and wetted by the anolyte and another or opposite surface in contact with air or other suitable source of oxygen.
In the recent past, a more effective and efficient metal/air fuel cell including an intermediate ion exchange section characterized by an ion exchange electrolyte or ionolyte between the cathode plate of a cathode section and the anode section and separated from the anolyte by an ion exchange membrane has been developed. That new and special fuel cell is the subject matter of my co-pending application for U.S. Pat. Ser. No. 458,835, for METAL/GAS FUEL CELL filed Jan. 18, 1983.
While the above noted new metal/air fuel cell is a highly effective and efficient fuel cell, its operation is dependent upon maintaining the anolyte and ionolyte solutions in proper chemical balance or condition, disposing of excess heat generated by fuel cell reaction; and disposing of the solid byproducts of fuel cell reaction. In the absence of special means for handling the anolyte and ionolyte for such a cell, the only manner in which to attain practical efficient operation of such a cell is to establish and maintain a continuous flow of fresh anolyte and ionolyte through the cell and to dispose of the used anolyte and ionolyte. Such practice is not economically practical, is extremely inconvenient and is such that it renders such a cell unsuitable for commercial exploitation or practical use.
In the practical application and use of fuel cells, a multiplicity or battery of cells must be provided to generate useful and necessary amounts of electric power. In the case of batteries of fuel cells which require that one or more electrolytes be continuously or intermittently conducted into, through and from sections of the several cells, it has been found that if single supplies of electrolytes are provided for a plurality of cells, the electrolytes serve as conductors, through which shunt currents flow. Such shunt currents short-circuit the related cells and prevent effective and efficient operation of the battery of cells. As a result of the above, in batteries of fuel cells in which fresh supplies of electrolytes must be conducted to, through and from the cells, it has, as a general rule, been necessary to provide separate, independent, electrolyte supply means for each cell in order to prevent the flow of shunt currents through the electrolytes and between the related cells.
Efforts by the prior art to eliminate or block a flow of shunt currents in and through common supplies of electrolytes for a multiplicity of related cells have included the insertion of ion filtered devices in electrolyte supply lines connected with each of the cells and the provision and use of elongate electrolyte supply lines, of dielectric material, for each cell and which are sufficiently small in cross-section and sufficiently long so that the internal resistance in the columns of electrolyte within them is sufficient to reduce the flow of shunt currents between related cells to a negligible or acceptable level. Such efforts and means to eliminate the flow of shunt currents in common supplies of electrolytes for batteries of fuel cells, while effective and practical in some special cirumstances, have been found to be inapplicable and unsuitable for practical use in many situations.